当期文章

白细胞介素18对CD4⁺PD-1⁺ T细胞的作用可能参与免疫性血小板减少症的发病过程

易岑¹, 张诚^2,3, 李培宁³, 李伟平², 周莹^2,*

¹武汉市第一医院检验科，武汉 430022；²大连医科大学附属第二医院血液内科，大连 116027；³大连医科大学基础医学院，大连 116044

摘要

本文旨在研究白细胞介素18 (interleukin-18, IL-18)对人外周血CD4⁺程序性死亡受体-1 (programmed death-1, PD-1)⁺ T细胞调控作用及机制，探讨IL-18 的作用是否参与免疫性血小板减少症(immune thrombocytopenia, ITP)的发病过程。收集ITP患者和健康对照受试者外周抗凝血样本，分离出健康对照外周血单个核细胞(peripheral blood mononuclear cells, PBMCs)，用免疫磁珠法分离出CD4⁺PD-1⁺ T细胞，建立T细胞、B细胞共培养体系，用ELISA法检测细胞培养液上清中IgG，IgM含量，用流式细胞术检测细胞因子和共刺激分子表达，用MitoSOX 线粒体超氧化物指示剂检测线粒体活性氧(reactive oxygenspecies, ROS)水平。结果显示，在IL-18 刺激下，健康对照CD4⁺PD-1⁺ T细胞表面CD40L和诱导性共刺激分子(inducible costimulator,ICOS)表达显著上调，该T细胞辅助B细胞产生抗体的能力显著增强。IL-18 刺激可提高健康对照CD4⁺PD-1⁺ T 细胞线粒体ROS水平，促进该T细胞分泌干扰素γ (interferon γ, IFN-γ)和肿瘤坏死因子α (tumor necrosis factor α, TNF-α)，IL-18的这种促进细胞因子分泌的作用可被ROS 清除剂MitoQ 抑制。相对于健康对照，ITP 患者血清可溶性PD-1 (soluble PD-1,sPD-1)水平显著提高。在IL-18 刺激下，健康对照CD4⁺ T细胞培养液上清中sPD-1 含量显著提高。以上结果提示，IL-18 可能通过调节线粒体ROS产生显著影响CD4⁺PD-1⁺ T细胞的功能，并可能通过PD-1 通路参与其免疫调控，从而参与ITP 的发病过程。

关键词： 免疫性血小板减少症; CD4⁺PD-1⁺ T细胞; 白细胞介素18; 线粒体活性氧

Effects of interleukin-18 on CD4⁺PD-1⁺ T cells may contribute to the pathogenesis of immune thrombocytopenia

YI Cen¹, ZHANG Cheng^2,3, LI Pei-Ning³, LI Wei-Ping², ZHOU Ying^2,*

¹Clinical Laboratory of Wuhan No. 1 Hospital, Wuhan 430022, China；²Department of Hematology, the Second Affiliated Hospital of Dalian Medical University, Dalian 116027, China；³College of Basic Medical Sciences, Dalian Medical University, Dalian 116044, China

Abstract

The aim of this study was to investigate the regulatory effect and mechanism of interleukin-18 (IL-18) on the function of human peripheral blood CD4⁺ programmed death-1 (PD-1)⁺ T cells , and to explore whether the role of IL-18 was involved in the pathogenesis of immune thrombocytopenia (ITP). Peripheral anticoagulant samples were collected from ITP patients and healthy control subjects, and peripheral blood mononuclear cells (PBMCs) from healthy controls were isolated. CD4⁺PD-1⁺ T cells were isolated by immunomagnetic bead method and used to establish T and B cells co-culture system. ELISA was used to detect the contents of IgG and IgM in cell culture supernatant. Flow cytometry was used to detect cytokine and co-stimulatory molecule expression levels. MitoSOX mitochondrial superoxide indicator was used to detect mitochondrial reactive oxygen species (ROS) levels. The results showed that, under IL-18 stimulation, the expression levels of CD40L and inducible co-stimulator (ICOS) on the surface of healthy control CD4⁺PD-1⁺ T cells were significantly up-regulated, and the abilities of these T cells to assist B cells in producing antibodies were significantly enhanced. IL-18 stimulation increased the mitochondrial ROS levels in healthy control CD4⁺PD-1⁺ T cells, promoting the secretion of interferon γ (IFN-γ) and tumor necrosis factor α (TNF-α) by these T cells. This cytokine secretion promoting effect of IL-18 was inhibited by the ROS scavenger MitoQ. Compared to the healthy controls, the serum soluble PD-1 (sPD-1) level in the ITP patients was significantly increased. Under IL-18 stimulation, the sPD-1 level in the supernatant of healthy control CD4⁺ T cell culture was significantly increased. These results suggest that IL-18 may affect the function of CD4⁺PD-1⁺ T cells by regulating the production of mitochondrial ROS, and participate in their immune regulation through PD-1 pathway, thereby contributing to the pathogenesis of ITP.

Key words: immune thrombocytopenia; CD4⁺PD-1⁺ T cells; IL-18; mitochondrial reactive oxygen species

收稿日期：　　录用日期：

通讯作者：周莹　　E-mail:

DOI: 10.13294/j.aps.2025.0084

引用本文：

易岑, 张诚, 李培宁, 李伟平, 周莹. 白细胞介素18对CD4⁺PD-1⁺ T细胞的作用可能参与免疫性血小板减少症的发病过程[J]. 生理学报 2026; 78 (2): 433-442.

YI Cen, ZHANG Cheng, LI Pei-Ning, LI Wei-Ping, ZHOU Ying. Effects of interleukin-18 on CD4⁺PD-1⁺ T cells may contribute to the pathogenesis of immune thrombocytopenia. Acta Physiol Sin 2026; 78 (2): 433-442 (in Chinese with English abstract).